1. Field of the Invention
The invention relates to the use of timing belts for transmitting power between driving and driven pulleys in a sewing machine.
2. Description of the Prior Art
It is well known to transmit power in a sewing machine to a rotatable loop taker through a belt connecting a driving pulley with a driven pulley which is affixed to the loop taker shaft. The belt and pulleys are generally provided with teeth to prevent slippage of the belt on the pulleys and a resulting disturbance of an established timing relationship between rotational movement of the loop taker and endwise reciprocation of a sewing needle. Nevertheless, it has been found that as the belt ages, and either stretches or becomes worn, teeth on the belt will sometimes jump over teeth on the pulleys.
It is a prime object of the present invention to prevent a belt from slipping on engaged pulleys in a sewing machine.
More particularly, it is an object of the present invention to preserve the timing relationship between movements of a belt driven loop taker, and a needle in a sewing machine.
It is another object of the invention to maintain teeth on a power transmitting timing belt in a sewing machine in positive engagement with the teeth of a driving and driven pulley which are operatively connected through the belt.
It is also an object of the invention to improve the performance of a belt drive in a sewing machine with only very simply constructed parts and with minimum cost.
Other objects and advantages of the invention will become apparent during a reading of the specification taken in connection with the accompanying drawings.